Page 72 - Electronic Navigation Cyber Book

coast based receivers/base stations) with supplementary data from
satellite based networks.

Vessel traffic services
In busy waters and harbours, a local vessel traffic service (VTS) may
exist to manage ship traffic. Here, AIS provides additional traffic
awareness and information about the configuration and movements of
ships.
Maritime Security
AIS enables authorities to identify specific vessels and their activity within
or near a nation's Exclusive Economic Zone. When AIS data is fused with
existing radar systems, authorities are able to differentiate between
vessels more easily. AIS data can be automatically processed to create
normalized activity patterns for individual vessels, which when breached,
create an alert, thus highlighting potential threats for more efficient use
of security assets. AIS improves maritime domain awareness and allows
for heightened security and control. Additionally, AIS can be applied
to freshwater river systems and lakes.
Aids to navigation
The AIS Aids to Navigation (AtoN) product standard was developed with
the ability to broadcast the positions and names of objects other than
vessels, such as navigational aid and marker positions and dynamic data
reflecting the marker's environment (e.g., currents and climatic
conditions). These aids can be located on shore, such as in alighthouse,
or on water, platforms, or buoys. The U.S. Coast Guard has suggested
that AIS might replace racon (radar beacons) currently used for
electronic navigation aids. [13] AtoN's enable authorities to remotely
monitor the status of a buoy, such as the status of the lantern, as well as
transmit live data from sensors (such as weather and sea state) located
on the buoy back to vessels fitted with AIS transceivers or local
authorities. An AtoN will broadcast its position and Identity along with all
the other information. The AtoN standard also permits the transmit of
'Virtual AtoN' positions whereby a single device may transmit messages
with a 'false' position such that an AtoN marker appears on electronic
charts, although a physical AtoN may not be present at that location.
Search and rescue
For coordinating on-scene resources of a marine search and
rescue (SAR) operation, it is imperative to have data on the position and
navigation status of other ships in the vicinity. In such cases, AIS can
provide additional information and enhance awareness of available
resources, even if the AIS range is limited to VHF radio range. The AIS
standard also envisioned the possible use on SAR aircraft, and included
a message (AIS Message 9) for aircraft to report their position. To aid

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